Storage unit for wafer-like articles



p 6, 1969 o. E. DE ROUSSE 3,467,242

STORAGE UNIT FOR WAFER-LIKE ARTICLES Filed March 4, 1968 2 sheetss heetloponwaowo can P a INVENTOR. DALE EDEROUSSE 36 BY ATTORNEYS Sept. 16,1969 n. E. DE ROUSSE 3,467,242

STORAGE UNIT FOR WAFER'LIKE ARTICLES Filed March 4, 1968 2 Sheqts-Sheet2 IN .V ENTOR.

,DALE E. DEROUSSE ATTORNEYS United States Patent 0,

U.S. Cl. 206-1 15 Claims ABSTRACT OF THE DISCLOSURE A storage unit forwafer-like articles, such as disks of semiconductor material adapted foruse in making integrated circuit chips. The storage unit is comprised ofa tray having a bottom and wall means cooperating with the bottom todefine a plurality of compartments for receiving wafer-like articles.The wall means is constructed to engage such an article only at specificpoints on its outer periphery when the article is supported on edge onthe tray bottom. A lid is used to cover the compartment and has flangemeans movable into sealing engagement with a lip on the upper margin ofthe tray. Means is provided to apply a predetermined downward force toan article in a compartment of the tray when the lid covers thecompartment and stacking means on the tray and lid is provided toposition a plurality of covered trays in a vertical stack.

This invention relates to improvements in article handling and storagecontainers and, more particularly, a storage container for wafer-likearticles, such as disks of semiconductor material for use in makingintegrated circuit chips.

While the present invention is adapted for storing a wide variety ofarticles, it is specifically adapted for use in handling and storingsemiconductor disks of the type described wherein a large number of suchdisks must oftentimes be moved from place to place and on which a numberof operations are performed prior to the cutting of the disks into smallpieces to define what is known in the trade as integrated circuit chips.Such disks are of the order of one to two inches in diameter and from to20 mils in thickness and are quite frangible. Thus, extreme care must betaken to assure that the disks will not be fractured during handlingand/or storage and also that the sides of the disks remain clean at alltimes and untouched by the hands or by tools. Even contact betweenadjacent disks can mar the side surfaces of the disks sufficiently tocause the disks to be rejected for their intended purpose.

Storage containers heretofore utilized in the handling of semiconductordisks have generally been undesirable for several reasons, one of whichis that they do not properly isolate the disks from each other when thedisks are in the container. Thus, adjacent disks may contact each otherdue to relative movement between the disks and the container when thelatter is handled and damage to the disk side surfaces can result.Moreover, conventional containers generally make no provision to keepthe side surfaces of the disks out of contact with adjacent wallstructure in the containers so as to avoid damage to the side surfacesof the disks.

The present invention is directed to an improved handling and storagecontainer for disks of the type described to circumvent the problemsassociated with conventional containers used in this field. To this end,the present invention includes a tray having a number of open topcompartments for receiving and supporting a number of wafer-likearticles on edge in a manner such that the articles are only in pointcontact at their outer periphery with the adjacent structure of the trayso as to leave the surfaces of the articles substantially untouchedduring handling and storage. Also, the tray is made so that ad-3,467,242 Patented Sept. 16, 1969 ICC jacent articles generally remainout of contact with each other. The tray can be molded to form aone-piece construction to simplify the construction and minimize itsexpense. Also, the material of the tray can be translucent to permitarticles to be observed therein when the tray is closed or it can belight-tight for use with articles having photosensitive surfaces.

A further important feature of the invention is the provision ofstructure for applying a predetermined downward force to the verticallydisposed articles in the compartments of the tray when the latter iscovered by a lid. This feature assures substantially no relativemovement between the articles and the tray when the storage unit ishandled, i.e., moved about from place to place. Such downward forceapplied to the articles can be chosen to prevent such relative movementbetween the articles and the tray while assuring that the articles willnot be stressed to the limit at which structural damage to the disksoccurs.

A further important feature of the invention is the provision of animproved seal on the upper margin of the tray and the outer margin ofthe lid wherein a lip on the tray is receivable within a pair of spacedflanges rigid to and extending downwardly from the lid itself. Thespacing between the flanges is less than the transverse thickness ofthelip and one of the flanges is resilient so that, when the lip is forcedinto the space between the flanges, the one flange will be displacedfrom its equilibrium position and will be biased toward the lip. Thus,the flanges will be in sealing engagement with the lip on opposed sidesof the same to thereby assure that dust, dirt and other foreign matterwill not enter the tray at this junction.

Still another aspect of the present invention is the provision ofstacking means on the bottom of the tray and the top of the lid wherebya number of storage units, each comprised of a tray covered by a lid,can be vertically stacked in a manner to avoid any substantial lateralor longitudinal movement of the units. To this end, each tray hasprojections which mate with a plurality of stacking devices on a lidtherebelow, the stacking devices providing abutments for the innerextremities of the projections and stops for the adjacent side faces ofthe projections. Thus, the tray of each storage unit is effectively heldagainst lateral or longitudinal movement with respect to the lid of thestorage unit immediately therebelow.

The primary object of this invention is, therefore, to provide animproved handling and storage unit for use with wafer-like articleswherein the articles are stored in a tray on edge and engaged by thestructure of the tray only at spaced, outer peripheral points to therebyleave the opposed surfaces of the articles substantially untouched andto assure effective isolation of the articles with respect to eachother.

Another object of this invention is to provide a storage unit of thetype described wherein structure is utilized to apply a predetermineddownward force to the articles in the compartments of the tray when alid covers the same to thereby prevent any relative movement of thearticles in the compartments and thereby more assuredly provide fordamage-free handling of the articles.

A further object of this invention is to provide a storage unit of thetype described which has an improved Other objects of this inventionwill become apparent as the following specification progresses,reference being had to the accompanying drawings for a preferredembodiment of the storage unit of the invention.

FIG. 1 is a top plan view of the tray forming a part of the storage unitof the present invention;

FIG. 2 is a cross-sectional view taken along line 22 of FIG. 1;

FIG. 3 is a fragmentary cross-sectional view taken along line 33 of FIG.2;

FIG. 4 is a side elevational view, partly broken away, of the tray witha packing tube disposed therewithin and with the lid removed from thetray;

FIG. 5 is an end elevational view, partly in section, of the tray andlid thereon, showing the way in which the packing tube is disposed tohold articles in the compartments of the tray;

FIG. 6 is a perspective view of the tray and lid show ing the stackingmeans therefor;

FIG. 7 is a fragmentary end elevational view of a pair of stacked trayswith the bottom tray having a lid thereon; and

FIG. 8 is an enlarged, fragmentary cross-sectional view of the lid,showing the sealing means therefor.

The storage unit of the present invention is broadly denoted by thenumeral 10 and includes an open top tray 12 and a lid 14 for movementinto coupled relationship with tray 12 for covering the same. Tray 12 isprovided with a plurality of open top compartments 16 for receivingwafer-like articles 18 therewithin when the articles are inserted intothe tray through the open top thereof.

Tray 12 has a bottom 20, a pair of spaced, generally parallel sidewalls22 and a pair of opposed end walls 24 spanning the distance betweensidewalls 22. Bottom 20 and walls 22 and 24 are substantiallyimperforate so that, when the open top of the tray is closed by lid 14,articles 18 within the tray are closed to the atmosphere.

For purposes of illustration only, tray 12 is provided with two rows ofcompartments 16 with the compartment rows extending substantiallyparallel to sidewalls 22. To this end, a central partition 26 spans thedistance between end walls 24 and is also parallel to sidewalls 22.Other tray configurations can be utilized, if desired. For instance,only a single compartment row may be provided or more than two such rowscan be provided.

Bottom 20 in the vicinity of each compartment row is transverselyV-shaped, as shown in FIG. 2, to define a pair of inner bottom, supportsurfaces 28 and 30 which converge toward each other as the lowermostextremity 32 of bottom 20 is approached. Also, the upper extremities ofinner surfaces 30 converge toward each other as partition 26 isapproached, whereby the portion of bottom 20 in the vicinity of surfaces30 defines an inverted V-shaped recess 34 as shown in FIG. 2. Surfaces28 and 30 are disposed for supporting an article 18 on edge with theouter periphery of the article being in substantially point contactrelationship to surfaces 28 and 30.

Tray 12 has a plurality of spaced walls 36 extending upwardly frombottom 20 and defining respective compartments 16. Each wall 36 has afirst side section 38, a second side section 40 and a central section 42interconnecting the bottom margins of side sections 38 and 40, thelatter having inner edges 44 and 46, respectively, which converge towardeach other as central section 42 is approached. Thus, edges 44 and 46define stretches extending upwardly relative to surfaces 30 and 28,respectively, for each compartment row and provide for the open topfeature of the corresponding compartment.

Central portion 42 has a post 48 which is rigid to each side thereofrespectively, posts 48 of each central portion 42 extending upwardlyfrom the adjacent lowermost extremity 32 of bottom 20. Wall 36 isadapted to contact an article 18 only at spaced points on the outerperiphery thereof when the article is supported on bottom surfaces 28and 30. To this end, there is a three-point contact of an article 18 inthe manner shown in FIGS. 2 and 3 when the article is disposed within aparticular compartment 16. As shown in FIG. 2, article 18 in the leftcompartment row contacts the corresponding wall 36 at points 50 and 52While the bottom extremity or peripheral margin of the article contactspost 48 of the next adjacent wall 36 as shown in FIG. 3. Thus, thearticle is in a slightly inclined position and is contacted by thestructure of tray 12 at five points, all of which points are on theouter periphery or edge of the article itself. Thus, the opposedsurfaces of the article are substantially out of engagement with theadjacent structure of tray 12.

The V-shaped configuration defined by bottom surfaces 28 and 30, whentaken in conjunction with walls 36, allows tray 12 to receive and storearticles 18 of different diameters as shown in FIG. 2. In each case,there will be a substantially five-point contact of the structure of thetray with the article and the article will generally assume theangularity shown in FIG. 3. The only difference will be that articles ofdifferent sizes will contact different points of tray 12. As shown inFIG. 2, the smaller article 18 on the right will contact points onbottom 20, wall 36 and post 48 which are lower than the correspondingpoints contacted by the larger diameter article 18 on the left.Regardless of the diameter of the article, the five-point contact willbe achieved. A maximum diameter of the article will be determined by thewidth of each compartment 16.

Tray 12 is preferably formed with all of its components molded together,whereby the tray can define a one-piece construction through the use ofwell-established molding techniques. If molded, the tray constructionwill be relatively inexpensive to manufacture and can be formed from anyone of a number of different materials, such as polypropylene orpolyethylene. Moreover, the material can be colored, can be translucentor can be light-impervious for situations where articles 18 havephotosensitive outer surfaces.

The configuration of tray 12 is suitable to permit articles 18 to beinserted and removed from the tray by vacuum holding techniques. Theshapes of edges 44 and 46 of each wall 36 allow the upper outerperiphery of each article to be disposed for engagement by a vacuumlifter and the latter can gently raise and lower an article withoutcausing the article to engage the adjacent walls 36.

Lit 14 is imperforate and is preferably formed from the same materialand in the same manner as tray 12. The lid thickness is substantiallyuniform throughout and its color can be the same or different from thatof tray 12. It may be translucent for easy identification of contentswithout removing the lid and the lid can be made available in relativelysoft material, such as polyethylene for use where the lid must beremoved often. On the other hand, the lid can be of relatively rigidmaterial, such as polypropylene, where the lid is to be removed only arelatively few number of times.

The lid has a pair of continuous, spaced flanges 54 and 56 adjacent toits outer periphery. These flanges depend from the lower surface 58 oflid 14 and are adapted to cooperate with a continuous lip 60 on theuppermost margin of tray 12 to provide an effective seal when lid 14covers tray 12.

Flange 54 has a pair of side faces 62 and 64 of different lengths topresent an edge 66 at the lowermost extremity of side face 64. Thespacing between faces 62 and 64 is such that flange 54 is resilient,i.e., can be displaced from the full line position in FIG. 8 to thedashed line position.

Flange 56 has an inner face provided with a pair of surface segments 68and 70 which converge toward each other to form an edge 72 substantiallyaligned with edge 66 of flange 54. The spacing between edges 66 and 72is less than the transverse width of lip 60 as shown in FIG. 8 so that,when the lip is forced between flanges 54 and 56, flange 54 will bedisplaced to the dashed line position and the edge 66 will bite" intothe inner surface 74 of lip 60. Thus, the lip will, in effect, besqueezed between the flanges and thereby be sealed by the engagement ofthe flanges with the lip.

Surface segment 70 of flange 56 is substantially complemental to theouter surface 76 of lip 60. Also, the uppermost and outermost edge 78 oflip 60 is in engagement with flange 56 at a location 80 (FIG. 8)adjacent to the junction between lid 14 and flange 56. Thus, flanges 54and 56 are in sealing engagement with lip 60 at three points to providea positive seal at all times when the lid covers the tray while flanges54 and 56 form a labyrinthine path which is closed at the three points.Since flange 54 is resilient, it will return to its equilibrium positionwhen the lid is removed from the tray.

Lid 14 is provided with stacking devices 82 on upper surface 84 (FIGS. 5and 6) which position stacking feet or projections 86 rigidly connect tobottom 20 of tray 12. To this end, each projection 86 extends intorecess 34 from the adjacent lowermost extremity 32 of bottom 20 as shownin FIG. 2, the projection being provided with fiat sides as shown inFIG. 4.

Each device 82 has a first section 88 which is to be disposed proximalto and alongside the outer side of a corresponding projection 86. Asecond section 90 is disposed at right angles to section 88 and isadapted to abut the innermost end 92 of the corresponding projection.Devices 82 are spaced apart in accordance with the spacing ofprojections 86 so that, when a tray 12 is placed on lid 14, projections86 will be immediately disposed in the proper positions alongsidesections 88 and abutting sections 90.

Means may be supplied to provide a downward force to articles 18 incompartments 16 when lid 14 closes tray 12 to thereby hold the articlesubstantially immovable in the compartment. To this end, a plastic,resilient packing tube 92 may be positioned on the articles in thecompartments and be of a size suflicient to cause deformation of thetube from a transversely circular or other configuration to theconfiguration shown in FIG. 5. As shown in FIG. 4, the unflexed tubeprojects above the lip 60 of tray 12. However, when lid 14 is placed onthe tray, the lid deforms the tube and pushes the latter into the trayand against the outer peripheries of articles 18 which are disposed onedge in compartments 16. Thus, the articles are subjected to individualdownward forces and are held generally in fixed locations in respectivecompartments. Thus, storage unit 10 can be subjected to shock andacceleration forces of relatively high values without causing damage tothe articles in the tray.

Preferably, tube 92 is formed from a suitable thermoplastic material andhas a restoring force selected to apply a substantially uniform downwardforce to the upper edges of a number of articles 18 of a given diameteror falling in a given range of diameters. Since the tube is looselyreceived in the tray on the articles, it will be readily removable fromthe tray when lid 14 has been removed therefrom.

In use, tray 12 is positioned to receive articles 18 and such articlescan be deposited on edge by a vacuum lifter in the respectivecompartments. After the articles have been placed in the tray, thepacking tubes 92 can be put on the articles, followed by the placing oflid 14 on the tray. The lid is forced downwardly so that lip 60 isforced in to the space between flanges 54 and 56. Flange 54 will deflectinwardy and will be biased against the inner surface 74 of lip 60 tothereby releasably hold the lip between the flanges. The storage unit 10is then complete and a number of such storage units can be verticallystacked in the manner shown in FIG. 7 due to the provision of stackingdevices 82 and projections 86.

When stored in tray 12, articles 18 will contact adjacent wall structureonly at the fixed points on the outer peripheries of the article. Thus,the side faces of each article remain substantially untouched at alltimes so that the articles can be subjected to operations which requireperfectly unmarred surfaces.

While one embodiment of the invention has been shown and described, itwill be apparent that other adaptations and modifications of this devicecan be made without departing from the true spirit and scope of theinvention.

What is claimed is:

1. A tray for wafer-like articles comprising: a receptacle having abottom and means cooperating with said bottom to define therewith aplurality of compartments with each compartment adapted to receive awafer-like article, said bottom being substantially V-shaped to presenta pair of bottom surfaces for each compartment respectively with eachpair of bottom surfaces converging toward each other as the lowermostextremity of the bottom is approached, said cooperating means includinga pair of spaced stretches adjacent to each bottom surface respectivelywith the stretches extending upwardly relative to respective bottomsurfaces, the stretches of each pair being spaced from the stretches ofan adjacent pair by a dis tance greater than the thickness of awafer-like article in the corresponding compartment with each stretchbeing disposed to engage the outer periphery of the article in pointcontacting relationship with respect thereto when the article issupported on the corresponding bottom surfaces.

2. A storage unit for wafer-like articles comprising: a tray having anupper margin and means therewithin defining a plurality of compartmentswith each compartment being generally vertically disposed and adapted toreceive a wafer-like article on edge; a lid movable into coupledrelationship to said upper margin and into covering relationship to saidcompartments; and means engageable with the lid and extending laterallyfrom the upper extremity of a wafer-like article in a compartment forapplying a predetermined downward force to said upper extremity of thearticle when the lid covers the compartment to thereby cause the articleto be held in a generally fixed location in the compartment.

3. A storage unit as set forth in claim 2, wherein said force applyingmeans includes a resilient device having a restoring force responsive tothe coupled relationship between said tray and said lid.

4. A storage unit as set forth in claim 3, wherein said compartments aredisposed in a row, force applying means including a resilient tubedisposed above and longitudinally of said row.

5. In a storage unit for wafer-like articles comprising: a tray adaptedto receive a plurality of wafer-like articles and having an upper margindefining a lip; a lid movable into covering relationship to said tray;and a pair of spaced flanges carried by said lid and disposed forreceiving said lip therebetween when said lid covers said tray, one ofsaid flanges being resilient and the spacing between the flanges beingless than the thickness of the lip therebetween, whereby said one flangewill be displaced with respect to its equilibrium position and will bebiased toward said lip to thereby cause said flanges to be in sealingengagement with the lip when the lid covers the tray.

6. In a storage unit as set forth in claim 5, wherein said lip has aninner surface and an outer surface, said inner and outer surfacesflaring outwardly as the uppermost extremity of said lip is approached,the flange adjacent to said inner surface of the lip being resilient,the other flange having an inner face substantially complemental to saidouter surface of the lip.

7. In a storage unit as set forth in claim 6, wherein the outer face ofthe inner flange is angularly disposed relative to said inner surface ofthe lip to present an edge in substantially line contact with said innersurface, said lip having an uppermost edge engageable with said otherflange adjacent to its junction with said lid, whereby the lid has athree-point engagement with said flanges.

8. In a storage unit for wafer-like articles comprising: a tray adaptedto receive a plurality of wafer-like articles and having a bottomprovided with an inverted V-shaped outer surface to define a pair ofrelatively convergent surface segments; a pair of spaced projectionssecured to each surface segment respectively and extending outwardlytherefrom toward the other surface segment; a lid movable into closingrelationship to said tray; and a pair of stacking devices on said lidfor the projections on each surface segment respectively, each of saiddevices extending upwardly from said lid and having a first, generallyflat section proximal to the outer side of corresponding projection anda second, generally flat section abutting the outer end of thecorresponding projection when the tray is supported on said lid, wherebythe tray is rendered substantially immovable laterally andlongitudinally of said p'rojections.

9. In a storage unit as set forth in claim 8, wherein said projectionsare generally parallel to each other and are molded to said tray, saiddevices being molded to said lid, the sections of each device beinggenerally perpendicular to each other.

10. A storage unit for Wafer-like articles comprising: a tray having abottom, a sidewall provided with a lip on its upper margin, and meanscooperating with said bottom to define therewith a plurality ofgenerally vertically disposed compartments with each compartment adaptedto receive a wafer-like article on edge, said bottom being substantiallyV-shaped to present a pair of inner bottom surfaces for each compartmentrespectively with each pair of inner bottom surfaces converging towardeach other as the lowermost extremity of said bottom is approached, saidcooperating means including a pair of spaced stretches adjacent to eachbottom surface respectively with the stretches extending upwardlyrelative to respective bottom surfaces, the stretches of each pair beingspaced apart a distance greater than the thickness of a wafer-likearticle in the corresponding compartment with each stretch beingdisposed to engage the outer periphery of the article in pointcontacting relationship with respect thereto when the article issupported on the corresponding bottom surfaces; means in eachcompartment respectively adjacent to said bottom for engaging thelowermost margin of an article in the respective compartment in pointcontacting relationship with respect thereto; a lid movable onto saidtray and into closing relationship to said compartments; a pair ofspaced flanges carried by said lid and disposed for receiving said liptherebetween with said flanges being in sealing engagement to said lip;means engageable with the lid for applying a predetermined force to theupper extremity of a wafer-like article in a compartment when the lidcovers the same; said bottom having an outer surface defining a recess;a pair of spaced projections for each side of said recess respectively,each pair of projections extending into said recess and toward the otherside of the same; and a pair of stacking devices for each pair ofprojections respectively, each device being secured to and extendingupwardly from said lid and having a first section proximal to the outerside of a corresponding projection and a second section abutting theouter end of the corresponding projection when the tray is supported onsaid lid to render the tray substantially immovable laterally andlongitudinally of said projections.

11. A tray for wafer-like articles comprising: a receptacle having abottom and means cooperating with said bottom to define therewith aplurality of compartments with each compartment adapted to receive awafer-like article, said bottom being substantially V-shaped to presenta pair of bottom surfaces for each compartment respectively with eachpair of bottom surfaces converging toward each other as the lowermostextremity of the bottom is approached, said cooperating means includinga plurality of spaced walls, each wall forming one boundary of anadjacent compartment and having a pair of spaced, innermost edgesadjacent to and extending upwardly relative to respective bottomsurfaces, each pair of adjacent walls being spaced apart a distancegreater than the thickness of a wafer-like article in the correspondingcompartment with the edges of each wall being disposed to engage theouter periphery of the article in point contacting relationship withrespect thereto when the article is supported on the correspondingbottom surfaces.

12. A tray as set forth in claim 11, wherein each wall has a sectionextending upwardly from a respective bottom surface and is provided withmeans interconnecting the sections thereof adjacent to said lowermostextremity of said bottom.

13. A tray for wafer-like articles comprising: a receptacle having abottom and means cooperating with said bottom to define therewith aplurality of compartments with each compartment adapted to receive awafer-like article, said bottom being substantially V-shaped to presenta pair of bottom surfaces for each compartment respectively with eachpair of bottom surfaces converging toward each other as the lowermostextremity of the bottom is approached, said cooperating means includinga pair of spaced stretches adjacent to each bottom surface respectivelywith the stretches extending upwardly relative to respective bottomsurfaces, the stretches of each pair being spaced from the stretches ofan adjacent pair by a distance greater than the thickness of awafer-like article in the corresponding compartment with each stretchbeing disposed to engage the outer periphery of the article in pointcontacting relationship with respect thereto when the article issupported on the corresponding bottom surfaces; and means in eachcompartment, respectively, adjacent to said bottom for engaging thelowermost margin of an article in the respective compartment in pointcontacting relationship with respect thereto.

14. A tray as set forth in claim 13, wherein said cooperating meansincludes a plurality of walls with each wall forming one boundary of anadjacent compartment, said engaging means including a post secured toeach wall respectively and being disposed above and extending upwardlyrelative to said lowermost extremity of said bottom.

15. A tray for wafer-like articles comprising: a receptacle having abottom and means cooperating with said bottom to define therewith aplurality of compartments with each compartment adapted to receive awafer-like article, said bottom being substantially V-shaped to presenta pair of bottom surfaces for each compartment respectively with eachpair of bottom surfaces converging toward each other as the lowermostextremity of the bottom is approached, said cooperating means includinga number of spaced walls, each wall forming one boundary of an adjacentcompartment and having a pair of spaced stretches adjacent to eachbottom surface, respectively, with the stretches extending upwardlyrelative to respective bottom surfaces and being in alignment with thestretches of the walls, whereby said compartments are disposed in a row,the stretches of each pair being spaced from the stretches of anadjacent pair by a distance greater than the thickness of a wafer-likearticle in the corresponding compartment with each stretch beingdisposed to engage the outer periphery of the article in pointcontacting relationship with respect thereto when the article issupported on the corresponding bottom surfaces, said receptacle having apair of spaced sides extending upwardly from said bottom, said sides,said bottom and said walls being molded together to form a one-piececonstruction.

References Cited UNITED STATES PATENTS 2,795,430 6/1957 Broad 206--723,349,937 10/1967 Duff et al. 206--1 3,346,137 10/1967 Ricci 220-97JAMES B. MARBERT, Primary Examiner

